Excess accumulation of glucocorticoid increases acid secretion and HCO3- reabsorption in the kidney. Reabsorption of HCO3-, which almost occurs at the proximal tubule, is mediated Na+ / H+ exchanger-3 (NHE-3) and H+ -ATPase on the apical membrane and the Na + /HCO3- cotransporter-1 (NBC-1)on the basolateral membrane. Impact of glucocorticoid was investigated by immunohistochemistry and electron microscopy to correlate the changes with the effect of in vivo dexamethasone treatment for the rat kidney proximal tubule. In a control group, immunoreactivity of NHE-3 was detected in the apical membrane and the brush borders of S1, S2 and 3 segments of the proximal tubule. Immunoreactivity of NBC-1 was detected in the basolateral membrane of S1 and S2 segments of the proximal tubule. Immunoreactivity of NHE-3 and NBC-1 protein was more pronounced in dexamethasone treated groups than the control group. Dexamethasone 1 mg/kg caused most intense immunoreactivity for NHE-3 and NBC-1 protein, however, 0.01 mg/kg and 0.1 mg/kg produced less intense immunoreactivity with no appreciable differences between these lower doses of dexamethasone groups. By electron microscopy, the tubular cells of S1 segment of the control group revealed numerous mitochondria, endocytic apparatuses, lysosomes and many basal cytoplasmic processes. In dexamethasone treated groups, the cells of S1 and S2 segments of the proximal tubule had more mitochodria and more basolateral invaginations and had an increased number of more elongated microvilli, compared with the control group. The cells of the S3 segment of the control group showed scant lateral interdigitations and had a few smaller mitochondria. The cells of the S3 segment of dexamethasone treated groups had many mitochodria and an increased number of microvilli in the brush border, but revealed no difference of basolateral invaginations among the different groups of dexamethasone. These results indicate that prolonged administration of excess glucocorticoid increases NHE-3 and NBC-1 protein, and the up-regulation of these proteins could result in increased HCO3 - reabsorption in the rat renal proximal tubules. It also suggests that these adaptive responses closely correlate to morphological alterations of proximal tubular epithelial cells.
Animals ; Cytoplasm ; Dexamethasone* ; Epithelial Cells ; Immunohistochemistry ; Kidney* ; Lysosomes ; Membranes ; Microscopy, Electron ; Microvilli ; Mitochondria ; Rats* ; Up-Regulation

Japanese encephalitis virus (JEV)may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. To investigate whether JEV infection induces apoptosis, we examined DNA fragmentation and apoptosis in the specific region of the JEV infected mouse brain by DNA oligonucleosomal laddering and in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)technique and immunohistochemical study. JEV infections in the mouse brain were detected in the telencephalon, the diencephalons, and the brain stem, but not in the cerebellum and the hippocampus. Fragmentation of cellular DNA into oligonucleosome-length ladders was only observed in tissue samples prepared from the cerebral cortex. In addition, the large number of TUNEL-positive cells was observed in the cerebral cortex. Double-labeling experiment with TUNEL staining and immunostaining for the JEV showed that TUNEL-positive neurons containing JEV immunoreactivity. These results suggest that JEV infection may evoke apoptotic neuronal death in the mouse brain, which plays an important role in the pathogenesis of Japanese encephalitis.
Animals ; Apoptosis ; Asian Continental Ancestry Group* ; Brain Stem ; Brain* ; Cells, Cultured ; Cerebellum ; Cerebral Cortex ; Diencephalon ; DNA ; DNA Fragmentation ; Encephalitis ; Encephalitis Virus, Japanese* ; Encephalitis, Japanese* ; Hippocampus ; Humans ; Immunohistochemistry ; In Situ Nick-End Labeling ; Mice* ; Neurons* ; Telencephalon

Macrophages in the corpus luteum have many important roles during the periods of functional development and luteal regression. Not only phagocyte the apoptotic luteal cells, but also they secrete many cytokines and exert their effects via autocrine/paracrine actions.In this study, we investigated the changes of number and immunoreactivity of macrophages at various developmental periods of the corpus luteum in the rat ovary. The rats (Sprague-Dawley strain, female)at age of 8 weeks (ovulatory period), GD 6 (pregnant period), and postpartum 5 days (postpartum period)were sacrificed under ether anesthesia and obtained both ovaries, one used for macrophages immunohistochemistry and the other used for TEM. The results were as follows; 1.In the corpora lutea of the rat, macrophages were observed all the developmental periods including ovulatory, pregnant and postpartum periods. 2.In the corpora lutea of the rat, number of macrophages was highest in the ovulatory period, and decreased at postpartum period and pregnant period in order. The immunoreactivity of macrophages was high at ovulatory period, moderate at postpartum period, and low at pregnant period. 3.In TEM observations, two types of macrophages were observed: One type was non-phagocytic macrophage and the other type was phagocytic macrophage. Phagocytic macrophages were observed in the corpora lutea at ovulatory and postpartum periods and contained apoptotic bodies, phagocytic vacuoles and many lipid droplets. Non-phagocytic macrophages were observed in the corpora lutea at pregnancy period and showed slender cell body with long cytoplasmic processes and contained no apoptotic bodies. In the rat, the number and the degree of immunoreactivity of macrophages in the corpus luteum varied with the changes of functional state of the corpus luteum. It was suggested that the main function of the macrophages at the ovulatory and postpartum periods was elimination of apoptotic luteal cells and that at pregnancy period was autocrine/paracrine action.Ultrastructurally, two types, phagocytic and nonphagocytic types, of macrophages confirmed. These results will provide valuable informations on the study of the role macrophages during development and regression of corpus luteum.
Anesthesia ; Animals ; Apoptosis ; Corpus Luteum* ; Cytokines ; Cytoplasm ; Ether ; Female ; Immunohistochemistry ; Luteal Cells ; Luteolysis ; Macrophages* ; Ovary ; Phagocytes ; Postpartum Period ; Pregnancy ; Rats* ; Vacuoles

No abstract available.
Animals ; Brain* ; Diencephalon* ; In Situ Hybridization* ; Rats* ; RNA, Messenger* ; Somatostatin* ; Telencephalon*

Although somatotropes of the pituitary gland which secret growth hormone occupy the highest percentage among pituitary hormone cells, the regulatory mechanism of the somatotropes has not been investigated as much as that of the mammotropes. The present study was performed to investigate the direct effects of estrogen on the somatotropes after estrogen treatment in culture of rat pituiary cells. Quantification of bromodeoxyuridine (BrdU)-labeled cells after double immunocytochemistry for BrdU and growth hormone (GH) or prolactin (PRL) demonstrated that estrogen treatment did not bring about the difference in either BrdU labeling index (BLI), apoptosis or cell number of somatotropes. In comparison, estrogen increased the BLI and relative cell number of mammotropes. It was suggested that the changes in the relative cell number of the somatotropes or mammotropes do not attribute to cell death, but to cell proliferation.
Animals ; Apoptosis ; Bromodeoxyuridine ; Cell Count ; Cell Death ; Cell Proliferation ; Estrogens* ; Growth Hormone ; Immunohistochemistry ; Pituitary Gland ; Prolactin ; Rats*

Parkinson's disease animal model was developed by the destruction of the striatonigral dopaminergic system. The morphological changes in the dopamine depleted striatum after the transplantation of the fetal mesencephalic dopaminergic neurons or tyrosine hydroxylase cDNA transfected human neural stem cells (C4-TH cells) were studied. Male Sprague-Dawley rats, weighting 250~300 gm, were used. To make unilateral lesion of nigrostriatal tract, 6-OHDA (6 microgram/microliter) was injected into the medial forebrain bundle. Two weeks after the lesion surgery, the effect of the 6-OHDA lesion was assessed by monitoring apomorphine (0.5 mg/kg, s.c)-induced turning behavior and confirmed by the lack of TH-immunoreactivity on tissue sections. Either cell suspension from ventral mesencephalic tissue obtained from embryonic day 14 fetus or C4-TH cells was grafted into the rostral striatum. After grafting, rats were tested with apomorphine every 2 weeks for 6 weeks. The grafted rats showing behavioral recovery were sacrificed and analysed by TH, neuropeptide Y (NPY), and parvalbumin (PV) immuno- histochemistry. TH-immunoreactive (ir) neurons were located around the graft and their processes extended into the striatum. The TH-ir axon terminals made a symmetrical synapse with the dendrites of the striatal neuron. Cell bodies either NPY- or PV-ir striatal neuron were observed around the graft and extended their processes into the graft. TH-ir C4-TH cells were also distributed along the needle track such as the transplanted fetal dopaminergic neurons, but had smaller soma and fewer processes than those. It is concluded that the grafted dopaminergic cells are survived in the dopamine depleted striatum and recovered the rotational behavior of Parkinson's disease animal model.
Animals ; Apomorphine ; Carisoprodol ; Cell Transplantation* ; Dendrites ; DNA, Complementary ; Dopamine ; Dopaminergic Neurons ; Fetus ; Humans ; Male ; Medial Forebrain Bundle ; Models, Animal* ; Needles ; Neural Stem Cells ; Neurons ; Neuropeptide Y ; Oxidopamine ; Parkinson Disease* ; Presynaptic Terminals ; Rats* ; Rats, Sprague-Dawley ; Synapses ; Transplantation ; Transplants* ; Tyrosine 3-Monooxygenase

No abstract available.
Pancreas* ; Stem Cells*

No abstract available.
Stem Cells*

Cornified envelope is highly insoluble structure formed beneath the plasma membrane during terminal differentiation of keratinocytes and is stabilized by cross linking of various proteins, including involucrin, loricrin, and cornifin. Psoriasis is a chronic skin disease characterizing inflammatory reaction and hyperproliferation of keratinocyte. There are some differences in involucrin immunolabelling in stratum corneum between normal and psoriasis epidermis. Labelling was convergent to cornified envelope in psoriasis skin but throughout cytoplasm in normal skin. To compare terminal differentiation patterns of normal and psoriasis keratinocytes, we reconstructed normal and psoriatic artificial skin by using primary cultured keratinocytes from normal and psoriasis skin and then performed immunogold labelling for involucrin in stratum corneum. Psoriatic artificial skin had thin and poorly organized corneal layer. Immunogold labelling for involucrin revealed same pattern of that in vivo by showing throughout cytoplasm in lower layer but convergent cornified envelope in upper layer. Compared with psoriatic artificial skin, normal artificial skin had well organized and thick stratum corneum. Involucrin labelling was throughout cytoplasm in most of corneal layer but convergent to cornified envelope in some uppermost cells. Even though some cells show convergent pattern in normal artificial skin, absolute number of this pattern was no lesser than in artificial psoriatic skin because of normal artificial skin had thick stratum corneum. This result showed there was no difference in involucrin distribution in terminal differentiation of normal and psoriasis keratinocytes in organotypic culture model. It is concluded that although well organized multiple corneal layers are formed in normal artificial skin, they can not reach to full maturation of cornified envelope, and difference of involucrin localization in cornified envelope of psoriasis epidermis is related with not peculiarities of the cells but rapid growing in vivo.
Cell Membrane ; Cytoplasm ; Epidermis ; Keratinocytes ; Psoriasis ; Skin ; Skin Diseases ; Skin, Artificial*

To be helpful in medical education, anatomical images were made by serial sectioning of the Korean cadaver's whole body at 0.2 mm intervals. Successively, segmented images were made by outline drawing of thirteen anatomical structures on the anatomical images. First purpose of this research is to verify that anatomical and segmented images are correct by means of the virtual dissection of 3D (three dimensional) images, which are made of the anatomical and segmented images. Second purpose is to verify that the virtual dissection is helpful in studying anatomy. A 3D anatomical image and a 3D segmented image were made by stacking the anatomical and segmented images and subsequently by volume reconstructing after both intervals and pixel size of the anatomical and segmented images were reduced to be 1 mm. Virtual dissection software, on which the 3D anatomical and 3D segmented images could be sectioned at free angles, and the 3D anatomical images of the several anatomical structures could be selected to display referring to the 3D segmented image and could be rotated at the free angles, was made. As the result of this research, corresponding 3D anatomical and 3D segmented images (resolution 494x282x1,702) were prepared; and virtual dissection software, which could be conveniently operated on the personal computer, was prepared. On the virtual dissection software, stereoscopic shape and location of the anatomical structures were corresponding to anatomical knowledge, so that the anatomical and segmented images were verified to be correct. The virtual dissection software was verified to be helpful in studying stereoscopic shape and location of the anatomical structures. If the anatomical images, segmented images, 3D images, and virtual dissection software made in this research are distributed worldwide, they will help not only medical students and doctors study anatomy but also other researchers make better segmented images, 3D images, and virtual dissection software.
Education, Medical ; Humans ; Microcomputers ; Students, Medical